Rotary tool with improved coupling assembly

ABSTRACT

A surgical device comprising: a handle assembly; a locking collar; and a set of replaceable bits that load into the handle assembly; wherein the locking collar is fully removable from the handle assembly, loads axially to a first position, and rotates between the first position and a second position; wherein, in the first position, the locking collar is free to be removed from the handle assembly and the replaceable bits are free to be loaded or unloaded from the handle assembly; wherein, in the second position, the locking collar is prevented from axial movement relative to the handle assembly and the replaceable bits are prevented from being received within, or removed from, the handle assembly; and the locking collar is guided to the first position and between the first position and the second position by a groove in the handle assembly mating with a member carried by the locking collar.

REFERENCE TO PENDING PRIOR PATENT APPLICATIONS

This patent application is a continuation of pending prior U.S. patentapplication Ser. No. 14/700,336, filed Apr. 30, 2015 by Gyrus ACMI,Inc., d.b.a. Olympus Surgical Technologies America and Kevin C. Edwardset al. for ROTARY TOOL WITH IMPROVED COUPLING ASSEMBLY, which claimsbenefit of prior U.S. Provisional Patent Application Ser. No.61/986,607, filed Apr. 30, 2014 by Gyrus ACMI, Inc., d.b.a. OlympusSurgical Technologies America and Kevin C. Edwards et al. for ROTARYTOOL WITH IMPROVED COUPLING.

The two (2) above-identified patent applications are hereby incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to surgical apparatus and procedures in general,and more particularly to rotary tools of the sort used to drive workingelements such as drill bits and burrs.

BACKGROUND OF THE INVENTION

In many surgical procedures, it is necessary or desirable to drill orabrade an object, e.g., bone. In these situations, it is common toprovide a rotary tool comprising a handle assembly having a high speedmotor, and a coupling assembly at the distal end of the handle assemblyfor releasably connecting a working element (e.g., a drill bit or burr)to the high speed motor, such that the working element (e.g., the drillbit or burr) can be turned by the high speed motor and then used for thedesired purpose (e.g., drilling or abrading bone).

The present invention provides a novel coupling assembly for releasablyconnecting a working element (e.g., a drill bit or burr) to a high speedmotor of a handle assembly of a rotary tool.

For purposes of clarity of description, the present invention willsometimes hereinafter be discussed in the context of a high speed drillbit or burr, however, it should be appreciated that the presentinvention is also applicable to other working elements, e.g., a dentalpolishing head, etc.

SUMMARY OF THE INVENTION

The present invention comprises the provision and use of a novelcoupling assembly for releasably connecting a working element (e.g., adrill bit or burr) to a high speed motor of a handle assembly of arotary tool.

For purposes of clarity of description, the present invention willsometimes hereinafter be discussed in the context of a high speed drillbit or burr, however, it should be appreciated that the presentinvention is also applicable to other working elements, e.g., a dentalpolishing head, etc.

In one preferred form of the invention, there is provided a surgicaldevice comprising:

-   -   a handle assembly;    -   a locking collar; and    -   a set of replaceable bits that load along an axis into said        handle assembly;    -   wherein said locking collar is fully removable from said handle        assembly, said locking collar loads axially to a first position,        and said locking collar rotates between said first position and        a second position;    -   wherein, in said first position, said locking collar is free to        be axially removed from said handle assembly and said        replaceable bits are free to be loaded or unloaded from said        handle assembly;    -   wherein, in said second position, said locking collar is        prevented from axial movement relative to said handle assembly        and said replaceable bits are prevented from being received        within, or removed from, said handle assembly; and    -   said locking collar is guided to said first position and between        said first position and said second position by a groove in said        handle assembly mating with a member carried by said locking        collar.

In another preferred form of the invention, there is provided a surgicaldevice comprising:

-   -   a handle assembly, said handle assembly comprising:        -   a collet sleeve, said collet sleeve comprising at least one            opening extending radially through said collet sleeve;        -   a hollow housing;        -   at least one canted cam slot formed in said hollow housing,            said at least one canted cam slot having a first end and a            second end;        -   a biasing collar, said biasing collar comprising at least            one biasing collar engagement element, said at least one            biasing collar engagement element extending through said at            least one canted cam slot and extending outwardly from the            outer surface of said hollow housing, said biasing collar            being configured to move between a first biasing collar            position and a second biasing collar position;        -   a cam element, said cam element being configured to move            between a first cam element position and a second cam            element position;        -   a biasing element, said biasing element biasing said cam            element towards said second cam element position; and        -   at least one locking element, said at least one locking            element being configured to move in said at least one            opening in said collet sleeve; and    -   a locking collar, wherein said locking collar is fully removable        from said handle assembly, and further wherein said locking        collar is configured to directly engage the portion of said at        least one biasing collar engagement element which extends        outwardly from the outer surface of said hollow housing and is        configured to rotate between a first locking collar position and        a second locking collar position;    -   wherein, when said locking collar is in its first locking collar        position, said at least one biasing collar engagement element is        engaged with said locking collar and is driven to said first end        of said at least one canted cam slot, causing said biasing        collar to be driven to said first biasing collar position, in        which position said biasing collar urges said cam element to        said first cam element position, and further wherein, with said        cam element in said first cam element position, said at least        one locking element is free to move radially outward in said at        least one opening of said collet sleeve; and    -   wherein rotation of said locking collar from said first locking        collar position to said second locking collar position causes        said at least one biasing collar engagement element to be driven        to said second end of said at least one canted cam slot, and        said biasing collar is driven to said second biasing collar        position, such that said biasing collar is retracted beyond the        travel of said cam element, allowing said biasing element to        drive said cam element to its said second cam element position,        in which position said at least one locking element is driven        into said at least one opening in said collet sleeve so that a        portion of said at least one locking element extends radially        inward from the inner wall of said collet sleeve.

In another preferred form of the invention, there is provided a methodfor securing a working element to a surgical device, said methodcomprising:

-   -   providing a surgical device comprising:        -   a handle assembly, said handle assembly comprising:            -   a collet sleeve, said collet sleeve comprising at least                one opening extending radially through said collet                sleeve;            -   a hollow housing;            -   at least one canted cam slot formed in said hollow                housing, said at least one canted cam slot having a                first end and a second end;            -   a biasing collar, said biasing collar comprising at                least one biasing collar engagement element, said at                least one biasing collar engagement element extending                through said at least one canted cam slot and extending                outwardly from the outer surface of said hollow housing,                said biasing collar being configured to move between a                first biasing collar position and a second biasing                collar position;            -   a cam element, said cam element being configured to move                between a first cam element position and a second cam                element position;            -   a biasing element, said biasing element biasing said cam                element towards said second cam element position; and            -   at least one locking element, said at least one locking                element being configured to move in said at least one                opening in said collet sleeve; and        -   a locking collar, wherein said locking collar is fully            removable from said handle assembly, and further wherein            said locking collar is configured to directly engage the            portion of said at least one biasing collar engagement            element which extends outwardly from the outer surface of            said hollow housing and is configured to rotate between a            first locking collar position and a second locking collar            position;        -   wherein, when said locking collar is in its first locking            collar position, said at least one biasing collar engagement            element is engaged with said locking collar and is driven to            said first end of said at least one canted cam slot, causing            said locking collar to be driven to said first locking            collar position, in which position said locking collar urges            said cam element to said first cam element position, and            further wherein, with said cam element in said first cam            element position, said at least one locking element is free            to move radially outward in said at least one opening in            said collet sleeve; and        -   wherein rotation of said locking collar from said first            locking collar position to said second locking collar            position causes said at least one biasing collar engagement            element to be driven to said second end of said at least one            canted cam slot, and said biasing collar is driven to said            second biasing collar position, such that said biasing            collar is retracted beyond the travel of said cam element,            allowing said biasing element to drive said cam element to            its said second cam element position, in which position said            at least one locking element is driven into said at least            one opening in said collet sleeve so that a portion of said            at least one locking element extends radially inward from            the inner wall of said collet sleeve;    -   rotating said locking collar so as to cause said biasing collar        to move said cam element into said first cam element position;    -   positioning the shaft of a working element in said collet        sleeve; and    -   rotating said locking collar so as to cause said biasing collar        to move so as to allow said cam element to assume its second cam        element position.

In another preferred form of the invention, there is provided a surgicaldevice comprising:

-   -   a handle assembly comprising a rotatable drive shaft;    -   a removable handle assembly adapter for connection to said        handle assembly, said removable handle assembly adapter        comprising a rotatable transmission shaft for connection to said        rotatable drive shaft of said handle assembly; and    -   a removable nosepiece assembly for connection to said removable        handle assembly adapter and for selectively securing the shaft        of a working element to said rotatable transmission shaft of        said removable handle assembly adapter;    -   wherein said removable handle assembly adapter and said        removable nosepiece assembly each comprise a locking collar; and    -   wherein said removable handle assembly adapter and said handle        assembly each comprise a connector assembly, said connector        assembly comprising:        -   a housing comprising an opening;        -   a collet sleeve disposed within said opening and connected            to an input shaft, said collet sleeve comprising a lumen for            receiving an output shaft;        -   a locking element movable relative to said collet sleeve            between (i) a locked position in which said output shaft is            secured to said collet sleeve, and (ii) an unlocked position            in which said output shaft is not secured to said collet            sleeve; and        -   a cam element movable relative to said collet sleeve            between (i) a first position in which said locking element            is free to assume its said unlocked position, and (ii) a            second position in which said cam element cams said locking            element into said locked position;    -   such that movement of said locking collar causes said cam        element to move between said first position and said second        position.

In another preferred form of the invention, there is provided a kitcomprising:

-   -   a handle assembly comprising a rotatable drive shaft;    -   a removable nosepiece assembly; and    -   a set of replaceable bits;    -   wherein said removable nosepiece assembly is configured for        mounting to said handle assembly and for accepting a replaceable        bit so that said replaceable bit is connected to said rotatable        drive shaft; and    -   a removable handle assembly adapter having a rotatable shaft,        said removable handle assembly adapter being configured at one        end for mounting to said handle assembly and being configured at        another end for receiving said nosepiece assembly so that said        replaceable bit is connected to said rotatable drive shaft via        said rotatable shaft of said removable handle assembly.

In another preferred form of the invention, there is provided a surgicaldevice comprising:

-   -   a handle assembly comprising

-   a powered drive shaft; and

-   a first connector assembly;    -   a removable nosepiece assembly for connection to said handle        assembly, said removable nosepiece assembly comprising:    -   a first shaft with a first shaft engagement portion for        connection to said powered drive shaft of said handle assembly;    -   a second shaft with a second shaft engagement portion for        connection to the shaft of a working element; and    -   a second connector assembly;    -   wherein each of said first and second connector assemblies        comprises:        -   a housing comprising an opening;        -   a collet sleeve disposed within said opening and connected            to an input shaft, said collet sleeve comprising a lumen for            receiving an output shaft;        -   a locking element movable relative to said collet sleeve            between (i) a locked position in which the output shaft is            secured to said collet sleeve, and (ii) an unlocked position            in which the output shaft is not secured to said collet            sleeve;        -   a cam element movable relative to said collet sleeve            between (i) a first position in which said locking element            is free to assume its said unlocked position, and (ii) a            second position in which said cam element cams said locking            element into said locked position; and        -   a locking collar mounted to said housing such that rotation            of said locking collar causes said cam element to move into            said second position.

In another preferred form of the invention, there is provided a surgicaldevice comprising:

-   -   a handle assembly comprising a rotatable drive shaft;    -   a removable handle assembly adapter for connection to said        handle assembly, said removable handle assembly adapter        comprising a rotatable transmission shaft for connection to said        rotatable drive shaft of said handle assembly; and    -   a removable nosepiece assembly for connection to said removable        handle assembly adapter and for selectively securing the shaft        of a working element to said rotatable transmission shaft of        said removable handle assembly adapter;    -   wherein at least one of said removable handle assembly adapter        and said removable nosepiece assembly comprises a removable        locking collar; and    -   wherein at least one of said removable handle assembly adapter        and said handle assembly comprises a connector assembly, said        connector assembly comprising:        -   a housing comprising an opening and a canted slot;        -   a collet sleeve disposed within said opening and connected            to an input shaft, said collet sleeve comprising a lumen for            receiving an output shaft;        -   a locking element radially movable relative to said collet            sleeve between (i) a locked position in which said output            shaft is secured to said collet sleeve, and (ii) an unlocked            position in which said output shaft is not secured to said            collet sleeve;        -   a cam element longitudinally movable relative to said collet            sleeve between (i) a first position in which said locking            element is free to assume its said unlocked position,            and (ii) a second position in which said cam element cams            said locking element into said locked position, said cam            element being yieldably biased into said second position;        -   a biasing collar for biasing said cam element into said            first position; and        -   an element extending through said canted slot and secured to            said biasing collar and said locking collar, such that            rotation of said locking collar causes said element to move            within said canted slot, whereby to cause said biasing            collar to move said cam element between said second position            and said first position.

In another preferred form of the invention, there is provided a methodfor securing a replaceable bit to a handpiecesurgical device, saidmethod comprising:

-   -   providing a surgical device comprising:        -   a handpiece handle comprising a powered rotatable drive            shaft;        -   a removable handpiece handle assembly adapter for connection            to said handpiecehandle assembly, said removable handpiece            handle assembly adapter comprising a rotatable transmission            shaft for connection to said powered rotatable drive shaft            of said handpiecehandle assembly; and        -   a removable coupling nosepiece assembly for connection to            said removable handpiece handle assembly adapter and for            selectively securing the shaft of a working element to said            rotatable transmission shaft of said removable handpiece            handle assembly adapter;        -   wherein at least one of said removable handle assembly            adapter and said removable nosepiece assembly comprises a            removable locking collar; and        -   wherein at least one of said removable handpiece handle            assembly adapter and said handpiece handle assembly            comprises a connector assembly, said connector assembly            comprising:            -   a housing comprising an opening and a canted slot;            -   a collet sleeve disposed within said opening and                connected to an input shaft, said collet sleeve                comprising a lumen for receiving an output shaft;            -   a locking element radially movable relative to said                collet sleeve between (i) a locked position in which the                said output shaft is secured to said collet sleeve,                and (ii) an unlocked position in which the said output                shaft is not secured to said collet sleeve;            -   a cam element longitudinally movable relative to said                collet sleeve between (i) a first position in which said                locking element is free to assume its said unlocked                position, and (ii) a second position in which said cam                element cams said locking element into said locked                position, said cam element being yieldably biased into                said second position;            -   a biasing collar for biasing said cam element into said                first position;            -   a locking collar removably mounted to said housing; and            -   an element extending through said helical canted slot                and secured to said biasing collar and said locking                collar, such that rotation of said locking collar causes                said element to move within said helical canted slot,                whereby to cause said biasing collar to move said cam                element into said first position;    -   rotating said locking collar so as to cause said biasing collar        to move said cam element into said first position;    -   positioning a shaft in said lumen of said collet sleeve; and    -   rotating said locking collar so as to cause said biasing collar        to move within said housing so as to allow said cam element to        assume its second position.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will bemore fully disclosed or rendered obvious by the following detaileddescription of the preferred embodiments of the invention, which is tobe considered together with the accompanying drawings wherein likenumbers refer to like parts and further wherein:

FIG. 1 is a schematic view showing a novel rotary tool provided inaccordance with the present invention;

FIG. 2 is an exploded schematic view of the novel rotary tool shown inFIG. 1;

FIG. 3 is a sectional schematic view of the novel rotary tool shown inFIG. 1;

FIGS. 4-13 are schematic views showing construction details of the novelrotary tool shown in FIG. 1;

FIGS. 14 and 15 are schematic views showing another novel rotary toolprovided in accordance with the present invention;

FIGS. 16 and 17 are schematic views showing still another novel rotarytool provided in accordance with the present invention;

FIGS. 18 and 19 are schematic views showing construction details of thenovel rotary tool shown in FIGS. 16 and 17;

FIGS. 20-24 are schematic views showing yet another novel rotary toolprovided in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention comprises the provision and use of a novelcoupling assembly for releasably connecting a working element (e.g., adrill bit or burr) to a high speed motor of a handle assembly of arotary tool.

For purposes of clarity of description, the present invention willsometimes hereinafter be discussed in the context of a high speed drillbit or burr, however, it should be appreciated that the presentinvention is also applicable to other working elements, e.g., a dentalpolishing head, etc.

Looking first at FIGS. 1-3, there is shown a novel rotary tool 5 forturning a working element (e.g., a drill bit or burr) 10. Rotary tool 5generally comprises a handle assembly 15 having a distal mount 20extending distally therefrom, and a nosepiece assembly 22 mountable to,and fully removable from, distal mount 20 of handle assembly 15.Nosepiece assembly 22 comprises a distal tip 23 for rotatably supportingworking element 10.

More particularly, handle assembly 15 comprises a cavity 25 having ahigh speed motor 30 (e.g., an 80,000 rpm motor) disposed therein. Distalmount 20 of handle assembly 15 comprises a cavity 35. Cavity 35 indistal mount 20 may be aligned with cavity 25 in handle assembly 15.High speed motor 30 turns a shaft 40 which extends into cavity 35 indistal mount 20.

A coupling assembly 45, generally disposed in distal mount 20 of handleassembly 15, releasably receives the shaft 50 of working element 10 andselectively couples the shaft of the working element to high speed motor30.

More particularly, and looking now at FIG. 4, coupling assembly 45generally comprises a collet sleeve 55 which is secured to shaft 40 ofhigh speed motor 30. Collet sleeve 55 is preferably connected to shaft40 of high speed motor 30 by a universal joint or a similar type ofconnector so as to minimize alignment and vibration issues. Colletsleeve 55 is sized to receive shaft 50 of working element 10 (FIG. 3),and comprises at least one opening 60 extending through the side wall ofcollet sleeve 55. In one preferred form of the invention, collet sleeve55 comprises three openings 60 extending through the side wall of colletsleeve 55. The three openings 60 may be equally-circumferentially spacedabout the longitudinal axis of collet sleeve 55. Collet sleeve 55 isrotatably mounted within cavity 35 of distal mount 20, e.g., by aplurality of bearings 65. In this way, when shaft 40 of high speed motor30 is turned, collet sleeve 55 is also turned. In one preferred form ofthe invention, there is provided a distal bearing 65A comprising aninner race 66A secured to collet sleeve 55 and an outer race 67A securedto distal mount 20; and a proximal bearing 65B comprising an inner race66B secured to collet sleeve 55 and an outer race 67B secured to distalmount 20.

In order for coupling assembly 45 to releasably secure shaft 50 ofworking element 10 to collet sleeve 55, coupling assembly 45 alsocomprises at least one collet ball 70 (or other locking element) whichis disposed in the at least one opening 60 of collet sleeve 55 (wherethree openings 60 are provided in collet sleeve 55, three collet balls70 may be provided, with one collet ball 70 being disposed in eachopening 60). Note that the at least one opening 60 of collet sleeve 55is configured so that the at least one collet ball 70 can protrude intothe central lumen 75 of collet sleeve 55, but the at least one colletball 70 cannot pass completely into central lumen 75 of collet sleeve 55due to the provision of shoulders 80 at the innermost points of the atleast one opening 60. In an alternative construction, the at least oneopening 60 comprises at least one tapered opening, in which caseshoulders 80 are replaced by the tapering side wall of the at least onetapered opening.

A cam element 85 is disposed about collet sleeve 55. Cam element 85comprises a first surface 90 and a second surface 95, with a transitionsurface 100 disposed therebetween. As will hereinafter be discussed,when first surface 90 of cam element 85 is aligned with the at least onecollet ball 70, the at least one collet ball 70 is free to move radiallyoutward to the extent necessary so that the at least one collet ball 70does not intrude into central lumen 75 of collet sleeve 55; at the sametime, when first surface 90 of cam element 85 is aligned with the atleast one collet ball 70, first surface 90 will prevent the at least onecollet ball 70 from completely exiting the at least one opening 60, sothat the at least one collet ball 70 will remain connected to colletsleeve 55. As a result, when first surface 90 of cam element 85 isaligned with the at least one collet ball 70, first surface 90 willlimit radially-outward movement of the at least one collet ball 70 andprevent the at least one collet ball 70 from “completely falling out of”the at least one opening 60 and becoming loose within cavity 35.However, when cam element 85 is moved proximally (e.g., under the powerof a spring 105 or other biasing element), transition surface 100 of camelement 85, and then second surface 95 of cam element 85, will engagethe at least one collet ball 70, whereby to cam the at least one colletball 70 radially inwardly, into central lumen 75 of collet sleeve 55(whereby to secure the shaft 50 of a working element 10 to collet sleeve55).

It should be appreciated that cam element 85 and spring 105 rotate inconjunction with collet sleeve 55, with spring 105 extending between theinner race 66A of distal bearing 65A and the distal end of cam element85.

Note that in one preferred construction, three collet balls 70 areprovided, one for each of three equally-circumferentially-spacedopenings 60, and shaft 50 of working element 10 has a triangularcross-section (FIG. 5), whereby to provide a secure, stable connectionbetween coupling assembly 45 and the shaft 50 of a working element 10when the three collet balls 70 are forced radially inwardly into contactwith the shaft 50 of a working element. Note also that, if desired, theat least one collet ball 70 can be replaced by at least one elementhaving a different configuration, e.g., the at least one collet ball 70may be replaced by at least one pin, by at least one finger, etc.

A biasing collar 110 (FIG. 4) is provided to selectively bias camelement 85 distally, against the power of its associated spring 105.More particularly, biasing collar 110 is itself biased distally by aspring 115 (or other biasing element), such that when biasing collar 110is unconstrained (see below), biasing collar 110 will engage theproximal end of cam element 85 so as to force cam element 85 distally,such that first surface 90 of cam element 85 is aligned with the atleast one collet ball 70 (FIG. 4). However, when biasing collar 110 isforced proximally (see below), against the power of spring 115, camelement 85 is free to move proximally under the power of its associatedspring 105, so that transition surface 100 of cam element 85, and thensecond surface 95 of cam element 85, engage the at least one collet ball70, whereby to cam the at least one collet ball 70 radially inwardly,into central lumen 75 of collet sleeve 55. In one preferred form of theinvention, biasing collar 110 rides against the inner surface of mount20 of handle assembly 15.

Note that spring 115 extends between the outer race 67B of proximalbearing 65B and the proximal end of biasing collar 110.

Note also that biasing collar 110 and spring 115 do not rotate withcollet sleeve 55 when collet sleeve 55 is rotated by high speed motor 30of handle assembly 15, as will hereinafter be discussed.

Means are provided for (i) selectively holding biasing collar 110proximally spaced from cam element 85 (even when cam element 85 isbiased proximally under the power of spring 105) so that frictionalforces are not created between cam element 85 (which rotates with shaft40 of high speed motor 30) and biasing collar 110 (which does not rotatewith shaft 40 of high speed motor 30), and (ii) allowing the user toforce biasing collar 110 proximally, against the power of spring 115, sothat cam element 85 can move proximally under the power of itsassociated spring 105 and thereby drive the at least one collet ball 70into central lumen 75 of collet sleeve 55, whereby to lock the shaft 50of a working element 10 within coupling assembly 45.

More particularly, and looking now at FIG. 6, at least one canted camslot 120 is provided in distal mount 20. The at least one canted camslot is canted with respect to the longitudinal axis of distal mount 20.The at least one canted cam slot 120 extends proximally andcircumferentially between a distalmost surface 125 and a proximalmostsurface 130. In one preferred form of the invention, the at least onecanted cam slot 120 has a substantially straight configuration. Inanother preferred form of the invention, the at least one canted camslot 120 has a substantially helical configuration. The at least onecanted cam slot 120 also comprises a canted cam extension 135 whichextends distally, and circumferentially, from proximalmost surface 130.At least one pin (or other element) 140 (FIG. 7), fixed to biasingcollar 110, extends radially through the at least one canted cam slot120 of distal mount 20, such that by moving the at least one pin 140from its distalmost position within the at least one canted cam slot 120(FIGS. 6 and 8), biasing collar 110 can be moved from its distalmostposition (FIG. 4) to its proximalmost position (FIG. 9). Thus, by movingthe at least one pin 140 proximally within the at least one canted camslot 120, biasing collar 110 can be moved proximally within distal mount20 so that cam element 85 is free to move proximally under the power ofspring 105, whereby to cam the at least one collet ball 70 radiallyinwardly, whereby to intrude into central lumen 75 of collet sleeve 55(e.g., to grip the shaft 50 of a working element 10 inserted intocentral lumen 75 of collet sleeve 55, or to prevent the shaft 50 of aworking element 10 from being inserted into central lumen 75 of colletsleeve 55). In one preferred form of the invention, the at least one pin140 is press fit or otherwise adhered to biasing collar 110.

In addition, by moving the at least one pin 140 into canted camextension 135 of the at least one canted cam slot 120 (FIG. 10), biasingcollar 110 is releasably held proximally spaced from cam element 85 sothat cam element 85 can cam the at least one collet ball 70 radiallyinwardly so as to grip the shaft 50 of a working element 10 (and also sothat no frictional forces will be created between rotating cam element85 and stationary biasing collar 110). In one preferred form of theinvention, two canted cam slots 120, which may be diametrically-opposedto one another, are provided in mount 20, each having an associatedcanted cam extension 135, and two diametrically-opposed pins 140 extendradially outward from biasing collar 110 and through the twodiametrically-opposed canted cam slots 120 (see FIG. 7).

Means are also provided for moving the at least one pin 140 within theat least one canted cam slot 120. More particularly, these means areprovided by the aforementioned nosepiece assembly 22.

Looking now at FIGS. 2, 3, 7 and 11, nosepiece assembly 22 comprisesmeans for supporting the shaft 50 of a working element 10 (e.g., distaltip 23, which may include bearings 142, see FIGS. 2 and 3) and a lockingcollar 145 (see FIGS. 7 and 11) disposed proximal to the aforementioneddistal tip 23. Locking collar 145 is rotatable relative to distal mount20 of handle assembly 15 when nosepiece assembly 22 is mounted to ahandle assembly 15. In one preferred form of the invention, lockingcollar 145 and distal tip 23 rotate as a unit. In another preferred formof the invention, locking collar 145 is rotatable relative to distal tip23. In either case, however, locking collar 145 is rotatable relative todistal mount 20 of handle assembly 15 when nosepiece assembly 22 ismounted to handle assembly 15. Note that where locking collar 145 isrotatable relative to distal tip 23, distal tip 23 is secured againstrotation relative to distal mount 20, e.g., by the provision of a keyingfeature such as male-female connection, where the male feature isprovided on one of the distal tip 23 and the distal mount 20, and thefemale feature is provided on the other of the distal tip 23 and thedistal mount 20.

Locking collar 145 generally comprises at least one groove (or slot) 150for receiving the radially-outermost portion of the at least one pin 140when nosepiece assembly 22 is mounted on distal mount 20 of handleassembly 15. As a result, when locking collar 145 is rotated, the atleast one pin 140 is also rotated, causing the at least one pin 140 tomove proximally within the at least one canted cam slot 120 of distalmount 120, and hence causing biasing collar 110 to move proximallywithin distal mount 20 (and hence allowing cam element 85 to moveproximally under the power of spring 105, whereby to cam the at leastone collet ball 70 radially inwardly into the lumen 75 of collet sleeve55). In one preferred form of the invention, where coupling assembly 45comprises two pins 140 extending through two canted cam slots 120 ofdistal mount 120, nosepiece assembly 22 comprises two grooves (or slots)150 for receiving the two diametrically-opposed pins 140. Where two pins140, two canted cam slots 120, and two grooves (or slots) 150 areprovided, each of the two pins 140, two canted cam slots 120, and twogrooves (or slots) 150 may be diametrically-opposed from one another.

In order to releasably lock nosepiece assembly 22 to distal mount 20,distal mount 20 comprises an L-shaped groove (or slot) 155 (FIG. 12)having a longitudinally-extending section 160 and acircumferentially-extending section 165. Locking collar 145 of nosepieceassembly 22 comprises a ball 170 (FIG. 11) which is received in L-shapedgroove (or slot) 155, i.e., ball 170 is received inlongitudinally-extending section 160 when nosepiece assembly 22 isadvanced onto distal mount 20 (or retracted off distal mount 20), andball 170 is received in circumferentially-extending section 165 whenlocking collar 145 is rotated so as to (i) lock the shaft 50 of aworking element 10 to coupling assembly 45 (and hence to handle assembly15), or (ii) unlock the shaft 50 of a working element 10 from couplingassembly 45 (and hence from handle assembly 15). If desired, ball 170can be replaced by a corresponding pin or finger or other element whichis connected to locking collar 145 and is received in L-shaped groove(or slot) 155.

Thus it will be seen that nosepiece assembly 22 can be mounted to distalmount 20 of handle assembly 15 by aligning ball 170 of nosepieceassembly 22 with longitudinally-extending section 160 of L-shaped groove(or slot) 155 of distal mount 20, and then moving the two parts togetheruntil ball 170 is aligned with circumferentially-extending section 165of L-shaped groove (or slot) 155 of distal mount 20. As this occurs, theat least one pin 140 of coupling assembly 45 is received in the at leastone groove (or slot) 150 of locking collar 145, and as nosepieceassembly 22 is mounted to distal mount 20 of handle assembly 15, the atleast one pin 140 of coupling assembly 45 is disposed at the distal end125 of the at least one canted cam slot 120 of distal mount 20. At thispoint, coupling assembly 45 is in the position shown in FIG. 4 (i.e.,unlocked).

Thereafter, the shaft 50 of a working element 10 may be advanced into,or retracted from, central lumen 75 of collet sleeve 55, since biasingcollar 110 will normally force cam element 85 distally, so that the atleast one collet ball 70 is free to move radially outward in the atleast one opening 60 in collet sleeve 55. The shaft 50 of a workingelement 10 can be advanced such that the at least one collet ball 70 isable to settle into at least one recess 175 (FIG. 13) formed in theshaft 50 of a working element 10. Note that in one preferred form of theinvention, where three equally-circumferentially-spaced openings 60 andthree collet balls 70 are provided, threeequally-circumferentially-spaced recesses 175 are also provided, suchthat each equally-circumferentially-spaced recess 175 can receive onecollet ball 70.

Locking collar 145 may then be rotated, whereby to cause the at leastone pin 140 to move within the at least one canted cam slot 120, wherebyto force biasing collar 110 proximally. As this occurs, cam element 85is free to move proximally, whereby to force the at least one colletball 70 radially inwardly, whereby to lock shaft 50 of working element(e.g., a drill bit or burr) 10 to coupling 45.

At the end of the rotation of locking collar 145, the at least one pin140 settles into canted cam extension 135 of the at least one canted camslot 120. With the at least one pin 140 settled into canted camextension 135 of the at least one canted cam slot 120, biasing collar110 is held proximally spaced from cam element 85, so that there is nofrictional contact between biasing collar 110 (which is rotationallystationary) and cam element 85 (which rotates with collet sleeve 55).

At this point, motor 30 may be energized so as to rotate its shaft 40,whereby to rotate collet sleeve 55 of coupling assembly 45, and hencerotate working element 10 (which is releasably secured to collet sleeve55). Working element 10 may then be used for its intended purpose, e.g.,to drill or abrade bone.

Thereafter, when working element 10 is to be released from handleassembly 15, locking collar 145 of nosepiece assembly 22 is rotatedagain, but this time in the opposite direction, whereby to cause the atleast one pin 140 to move out of canted cam extension 135 of the atleast one canted cam slot 120, and then distally along the at least onecanted cam slot 120, whereby to cause biasing collar 110 to movedistally, such that cam element 85 also moves distally. As this occurs,cam element 85 allows the at least one collet ball 70 to move radiallyoutwardly, whereby to free shaft 50 of working element 10 from handleassembly 15.

Note that in one preferred form of the invention, when the at least onepin 140 is in the at least one canted cam slot 120, the power of spring115 alone is insufficient to drive biasing collar 110 distally (andhence insufficient to drive the at least one pin 140 distally, and henceinsufficient to rotate locking collar 145 about distal mount 20). Inthis form of the invention, manual movement of locking collar 145 isrequired to drive biasing collar 110 distally (and hence to drive the atleast one pin 140 distally, and hence to rotate locking collar 145 aboutdistal mount 20).

However, in another form of the invention, when the at least one pin 140is in the at least one canted cam slot 120, the power of spring 115alone is sufficient to drive biasing collar 110 distally (and hencesufficient to drive the at least one pin 140 distally, and hencesufficient to rotate locking collar 145 about distal mount 20). In thisform of the invention, manual motion of locking collar 145 is onlynecessary to move the at least one pin 140 out of canted cam extension135 and into the at least one canted cam slot 120, and manual motion oflocking collar 145 is not thereafter required to drive biasing collar110 distally (and hence to drive the at least one pin 140 distally, andhence to rotate locking collar 145 about distal mount 20).

In one preferred form of the invention, theequally-circumferentially-spaced recesses 175 may be provided in sets(e.g., sets of three equally-circumferentially-spaced recesses), andmultiple sets of the equally-circumferentially-spaced recesses 175 maybe provided in axially-spaced locations along shaft 50 of workingelement 10, such that shafts of differing lengths may be accommodated.By way of example but not limitation, see FIGS. 3 and 13, which showfour axially-spaced sets of three equally-circumferentially-spacedrecesses 175 (i.e., 175A, 175B, 175C, 175D) formed in shaft 50 ofworking element 10.

If desired, the at least one pin 140 may be replaced by at least oneother element, e.g., at least one ball. Where a ball is used in place ofa pin, the ball may be retained in a pocket formed in biasing collar110, and in another pocket formed in locking collar 145, with the ballextending through the at least one canted cam slot 120. However, the useof a pin offers significant advantages over the use of a ball, since (i)a pin can be press fit to biasing collar 110, which provides a fast andsimple connection between biasing collar 110 and the pin; (ii) theheight of a pin is independent of the width of the pin, whereas the“height” of a ball is the same as the “width” of the ball—so that as the“height” of the ball is increased to make a secure engagement withlocking collar 145, the “width” of the ball must increase as well; and(iii) a pin generally makes a better camming contact with the at leastone canted cam slot 120 than a ball. For at least these reasons, it isgenerally preferred to use a pin (rather than a ball) to connect biasingcollar 110 to locking collar 145.

As seen in FIGS. 14 and 15, distal tip 23 of nosepiece assembly 22 mayinclude a curved extension 180 for rotatably receiving a working element10 having a flexible shaft. Note that where nosepiece assembly 22comprises a curved extension 180 and working element 10 comprises aflexible shaft, it is common to drive the working element 10 at a slowerspeed than where the working element 10 is substantially straight andrigid, in order to reduce the stress on the flexible shaft of theworking element 10 and thereby help preserve its working life. To thisend, it can be advantageous to provide handle assembly 15 with means fordetecting when distal tip 23 of nosepiece assembly 22 comprises a curvedextension 180. In one preferred form of the invention, and looking nowat FIG. 15, handle assembly 15 can include a plurality of Hall sensors185, and nosepiece assembly 22 (comprising a distal tip 23 having acurved extension 180) can include a plurality of magnets 190, such thathandle assembly 15 can detect when a nosepiece assembly 22 (of the sortcomprising a distal tip 23 having a curved extension 180) is mounted tohandle assembly 15 (and hence reduce the operating speed of motor 30 soas to preserve the working life of the working element 10).

Note that, if desired, and as shown in FIGS. 14 and 15, bearings 142 maybe omitted from nosepiece assembly 22, and shaft 50 of a working element10 may be supported by a simple sliding contact made directly againstnosepiece assembly 22.

As noted above, in accordance with the present invention, nosepieceassembly 22 is configured as a separate element from handle assembly 15,and is mountable to, and fully removable from, distal mount 20 of handleassembly 15.

It should be appreciated that, by providing nosepiece assembly 22 as afully-separable element from handle assembly 15, it is possible toprovide a wide variety of different nosepiece assemblies 22, with eachnosepiece assembly 22 being configured for a different purpose (e.g.,for performing a different task, for supporting a differently-configuredworking element, etc.), with each nosepiece assembly 22 comprising adistal tip 23 for slidably supporting a working tool 10 and a lockingcollar 145 for engaging the at least one pin 140 of a coupling assembly45 disposed in distal mount 20 of handle assembly 15.

Significantly, the nosepiece assembly may be configured to provide anangled shaft configuration. In this form of the invention, and lookingnow at FIGS. 16-19, there is provided a nosepiece assembly 22A whichcomprises the aforementioned locking collar 145 for engaging the atleast one pin 140 of coupling assembly 45 of handle assembly 15, and theaforementioned distal tip 23 for slidably receiving the shaft 50 of aworking tool 10. However, in this form of the invention, nosepieceassembly 22A also comprises a second coupling assembly 45A, a secondlocking collar 145A, and a pair of shafts 195, 200. Second couplingassembly 45A is substantially the same as the coupling assembly 45previously disclosed, except that it is disposed in nosepiece assembly122A distal to locking collar 145. Second locking collar 145A isprovided on nosepiece assembly 22A and is configured to engage the atleast one pin 140A of second coupling assembly 45A, whereby to lock orunlock a working element 10 to second coupling assembly 45A. Shaft 200is received by the aforementioned coupling assembly 45 in distal mount20 of handle assembly 15 when nosepiece assembly 22 is mounted to handleassembly 15, such that when locking collar 145 is rotated, shaft 195 ismechanically connected (via coupling assembly 45 in distal mount 20 ofhandle assembly 15) to drive shaft 40 of high speed motor 30. Shaft 195includes a beveled gear 205 at its distal end. Shaft 200 is connected tocollet sleeve 55A of coupling assembly 45A, and includes a beveled gear210 at its proximal end which is rotatably connected to gear 205 ofshaft 195, such that when shaft 40 of high speed motor 30 is rotated,collet sleeve 55A is also rotated (i.e., via the intervening colletsleeve 55 of coupling assembly 45 of handle assembly 15, and via theintervening shaft 195 and shaft 200 of nosepiece assembly 22). In thisform of the invention, second coupling 45A of nosepiece assembly 22releasably receives the shaft 50 of working element 10. Second lockingcollar 145A of nosepiece assembly 22A is used to selectively lock/unlockthe shaft 50 of a working element 10 to second coupling assembly 45A ofnosepiece 22A.

Significantly, by forming nosepiece assembly 22A so that thelongitudinal axis of shaft 195 is set at an angle to the longitudinalaxis of collet sleeve 55A of second coupling 45A, “off-angle” drillingcan be effected without requiring the use of a nosepiece assembly havinga curved extension 180 and a drill bit having a flexible shaft. This isa significant advance in the art, since it allows high speed “off angle”drilling or burring to be effected for prolonged periods of time withoutunduly limiting the life of working element 10.

If desired, the angled shaft nosepiece assembly 22A (FIGS. 16-19) can beprovided as a single assembly, which mounts and dismounts as a unit fromdistal mount 20 of handle assembly 15.

Alternatively, if desired, and looking now at FIGS. 20-24, there isshown a nosepiece assembly 22B which comprises (i) a nosepiece assembly22C, and (ii) a handle assembly adapter 22D, wherein nosepiece assembly22C and handle assembly adapter 22D are separable from one another(FIGS. 20-22), but may be connected together, e.g., at the time ofmanufacture, at the time of use, etc. (FIGS. 23 and 24), so as totogether form the complete nosepiece assembly 22B. The nosepieceassembly 22B may be an angled shaft nosepiece assembly.

In this form of the invention, nosepiece assembly 22C may be identicalto the aforementioned nosepiece assembly 22, i.e., nosepiece assembly22C comprises a distal tip 23C and a locking collar 145C.

In this form of the invention, handle assembly adapter 22D may comprisea distal mount 20D containing a coupling assembly 45D which receives theshaft 50 of a working element 10 and is activated by locking collar 145Cof nosepiece assembly 22C. And in this form of the invention, handleassembly adapter 22D may comprise a shaft 195D for being received incoupling assembly 45 in distal mount 20 of handle assembly 15, and ashaft 200D for transferring the rotation of shaft 195D to collet sleeve55D of coupling assembly 45D disposed in handle assembly adapter 22D(and hence transferring rotation of shaft 195D to the shaft 50 of aworking element 10 disposed in central lumen 75D of collet sleeve 55D).In this form of the invention, handle assembly adapter 22D comprises alocking collar 145D for actuating coupling assembly 45 in distal mount20 of handle assembly 15. It will also be appreciated that in this formof the invention, handle assembly adapter 22D is releasably secured todistal mount 20 of handle assembly 15 by loading locking collar 145D ofhandle assembly adapter 22D onto distal mount 20 of handle assembly 15in a manner analogous to the manner in which nosepiece assembly 22 ismounted onto distal mount 20 of handle assembly 15, and in this form ofthe invention, nosepiece assembly 22C is releasably secured to distalmount 20D of handle assembly adapter 22D by loading locking collar 145Cof nosepiece assembly 22C onto distal mount 20D of handle assemblyadapter 22D in a manner analogous to the manner in which nosepieceassembly 22 is mounted onto distal mount 20 of handle assembly 15.

Thus it will be seen that, in this form of the invention, nosepieceassembly 22B comprises a first mounting mechanism comprising a lockingcollar 145D for securing handle assembly adapter 22D to distal mount 20of handle assembly 15, and a second mounting mechanism for securingnosepiece assembly 22C to distal mount 20D of handle assembly adapter22D. However, it should also be appreciated that, if desired, analternative mounting mechanism may be used to secure handle assemblyadapter 22D to distal mount 20 of handle assembly 15 (while still usinga locking collar 145C to secure nosepiece assembly 22C to handleassembly adapter 22D); and/or an alternative mounting mechanism may beused to secure nosepiece assembly 22C to handle assembly adapter 22D(while still using the aforementioned locking collar 145D to securehandle assembly adapter 22D to distal mount 20 of handle assembly 15).

Modifications of the Preferred Embodiments

It should be understood that many additional changes in the details,materials, steps and arrangements of parts, which have been hereindescribed and illustrated in order to explain the nature of the presentinvention, may be made by those skilled in the art while still remainingwithin the principles and scope of the invention.

What is claimed is:
 1. A surgical device comprising: a handle assemblycomprising a rotatable drive shaft; a removable handle assembly adapterfor connection to said handle assembly, said removable handle assemblyadapter comprising a rotatable transmission shaft for connection to saidrotatable drive shaft of said handle assembly; and a removable nosepieceassembly for connection to said removable handle assembly adapter andfor selectively securing the shaft of a working element to saidrotatable transmission shaft of said removable handle assembly adapter;wherein said removable handle assembly adapter and said removablenosepiece assembly each comprise a locking collar; and wherein saidremovable handle assembly adapter and said handle assembly each comprisea connector assembly, said connector assembly comprising: a housingcomprising an opening; a collet sleeve disposed within said opening andconnected to an input shaft, said collet sleeve comprising a lumen forreceiving an output shaft; a locking element movable relative to saidcollet sleeve between (i) a locked position in which said output shaftis secured to said collet sleeve, and (ii) an unlocked position in whichsaid output shaft is not secured to said collet sleeve; and a camelement movable relative to said collet sleeve between (i) a firstposition in which said locking element is free to assume its saidunlocked position, and (ii) a second position in which said cam elementcams said locking element into said locked position; such that movementof said locking collar causes said cam element to move between saidfirst position and said second position.
 2. A surgical device accordingto claim 1 wherein said connector assembly of said handle assembly isconfigured to receive said rotatable transmission shaft of saidremovable handle assembly adapter in order to secure said rotatabletransmission shaft of said removable handle assembly adapter to saidrotatable drive shaft of said handle assembly, and said connectorassembly of said removable handle assembly adapter is configured toreceive a shaft of a working element, in order to secure the shaft ofthe working element to said collet sleeve of said connector assembly ofsaid removable handle assembly adapter.
 3. A surgical device accordingto claim 1 wherein said housing comprises an L-shaped slot, and furtherwherein said locking collar comprises an follower for extending intosaid L-shaped slot.
 4. A surgical device according to claim 3 whereinsaid L-shaped slot comprises a first leg and a second leg, and furtherwherein said first leg extends longitudinally along said housing andsaid second leg extends circumferentially along said housing.
 5. Asurgical device according to claim 4 wherein said follower is disposedin said first leg of said L-shaped slot when said locking collar isbeing mounted onto, or dismounted from, said housing, and furtherwherein said follower is disposed in said second leg of said L-shapedslot when said locking collar is rotated so as to cause said biasingcollar to move said cam element into said second position.
 6. A surgicaldevice according to claim 1 further comprising a working elementcomprising a shaft.
 7. A surgical device comprising: a handle assemblycomprising a powered drive shaft; and a first connector assembly; aremovable nosepiece assembly for connection to said handle assembly,said removable nosepiece assembly comprising: a first shaft with a firstshaft engagement portion for connection to said powered drive shaft ofsaid handle assembly; a second shaft with a second shaft engagementportion for connection to the shaft of a working element; and a secondconnector assembly; wherein each of said first and second connectorassemblies comprises: a housing comprising an opening; a collet sleevedisposed within said opening and connected to an input shaft, saidcollet sleeve comprising a lumen for receiving an output shaft; alocking element movable relative to said collet sleeve between (i) alocked position in which the output shaft is secured to said colletsleeve, and (ii) an unlocked position in which the output shaft is notsecured to said collet sleeve; a cam element movable relative to saidcollet sleeve between (i) a first position in which said locking elementis free to assume its said unlocked position, and (ii) a second positionin which said cam element cams said locking element into said lockedposition; and a locking collar mounted to said housing such thatrotation of said locking collar causes said cam element to move intosaid second position.